New rules for vaccine production

New US government guidelines on flu vaccines mean that
there may be a move away from the traditional method of brewing vaccines in
chicken eggs, towards the more modern recipe of making vaccines in banks of
cells.

Even though it may be years before this new process is broadly adopted,
manufacturers have been granted millions of dollars in research funds to develop
the technology as quickly as possible. This may help to boost the production of
avian
influenza vaccines in the case of a pandemic, as current methods may mean
factories cannot make vaccines fast enough to keep up with demand.

"Once you run out of eggs, you can't make more vaccine. But if you have
cells banked, you can always make more vaccine," explained Philip Krause, the Food and Drug Administration's
deputy director of viral vaccines.

Banks of cells taken either from animals or people already are used to make
numerous medical products, including a host of vaccines that protect against
such diseases as polio and chickenpox.

Today's egg-based flu vaccine has proven to be effective, but it requires
growing flu virus inside tens of millions of eggs from specially raised hens
months before the fall vaccination season begins.

The main advantage of the cell-based system is that it would enable faster
production if a new flu strain suddenly appeared, because makers wouldn't be
limited by availability of the special eggs.